1. Field of the Invention
The present invention relates to a laminated type heat exchanger used for an evaporator comprising an air conditioner mounted in a car.
2. Description of the Related Art
FIGS. 5 and 6 are a partial side view and a partial plan view which show a conventional laminated type heat exchanger used for an evaporator comprising an air conditioner mounted in a car, and FIG. 7 is a sectional view showing a cross-section along line Axe2x80x94A of FIG. 6.
In FIGS. 5, 6, and 7, a laminated type heat exchanger 1 comprises a plurality of tube elements 2 and cooling fins 4 which use air. The tube elements 2 are arranged parallel to each other with the cooling fins inter posed therebetween. The tube elements 2 and the cooling fins 4 are integrally soldered.
The tube element 2 comprises a pair of molded plates 2a and 2b. A refrigerant inlet chamber 20a, a refrigerant outlet chamber 20b, and a U-shaped refrigerant pipe 21 are formed by attaching the molded plates 2a and 2b. The refrigerant pipe 21 connects the refrigerant inlet chamber 20a with the refrigerant outlet chamber 20b. Therefore, the refrigerant flows from the refrigerant inlet chamber 20a to the refrigerant outlet chamber 20b via the refrigerant pipe 21. Moreover, a wave shaped plate 3 is mounted in the refrigerant pipe 21.
An end tube element 50 is formed by attaching an end plate 5 to the molded plate 2b which is positioned at one side of the laminated type heat exchanger 1. An end tube element 60 is formed by attaching an end plate 6 to the molded plate 2a at the other end of the laminated type heat exchanger 1. Thereby, a refrigerant inlet tank comprising a plurality of refrigerant inlet chambers 20a and a refrigerant outlet tank comprising a plurality of refrigerant outlet chambers 20b are formed.
A refrigerant gate portion 7 is soldered to the end tube element 50. The refrigerant gate portion 7 comprises a front plate 70 having flanges 9a and 9b for mounting an expansion valve 10, and a connection plate 8 having a passage 80a for flowing the refrigerant to the refrigerant inlet tank and a passage (not shown in the figures) for flowing the refrigerant from the refrigerant outlet tank.
In this conventional laminated type heat exchanger 1, the flow rate of the refrigerant send by the expansion valve 10 into the refrigerant inlet tank is not sufficient. Therefore, a short circuit is generated. In other words, most of the refrigerant send by the expansion valve 10 flows into the refrigerant pipe 21 arranged near the refrigerant gate portion 7, and reaches the refrigerant outlet tank. It is difficult for the refrigerant to reach the inner laminated type heat exchanger 1, namely the end tube element 60. A problem arises in that the refrigerant cannot be dispersed uniformly.
In consideration of the above described problem of the conventional technology, an object of the present invention is to provide a laminated type heat exchanger which can disperse the refrigerant uniformly.
A first laminated type heat exchanger of the present invention comprising:
a refrigerant inlet tank comprising a plurality of refrigerant inlet chambers, and in which a refrigerant passage passing through the refrigerant inlet chambers is formed;
a refrigerant outlet tank comprising a plurality of refrigerant outlet chambers, and in which a refrigerant passage passing through the refrigerant inlet chambers is formed;
a plurality of refrigerant pipes each having one end which is connected to the refrigerant inlet chamber and the other end which is connected to the refrigerant outlet chamber;
a refrigerant gate portion for flowing the refrigerant into the refrigerant inlet tank and from the refrigerant outlet tank;
a dispersion pipe which is inserted in the refrigerant passage formed in the refrigerant inlet tank;
wherein the length of the dispersion pipe is ⅓xcx9cxc2xc of the length of the refrigerant passage in the refrigerant inlet tank,
the sectional area of the dispersion pipe is smaller than that of the refrigerant passage in the refrigerant inlet tank,
a plurality of dispersion holes are formed at the opposite side of the dispersion pipe against the refrigerant pipe, and
the size of the dispersion holes increases with an increase in the distance from the refrigerant gate portion.
According to the first laminated type heat exchanger, a refrigerant in the dispersion pipe passes through the refrigerant inlet tank with maintaining a sufficient flow rate. Therefore, the refrigerant reaches the inner refrigerant inlet chambers. Moreover, the size of the dispersion holes increases with an increase in the distance from the refrigerant gate portion. Therefore, the refrigerant flows uniformly into the refrigerant pipes connected to the refrigerant inlet chambers. Then, the refrigerant is dispersed uniformly in the laminated type heat exchanger.
In a second laminated type heat exchanger of the present invention, at least one dispersion plate comprising an opening is provided in the refrigerant inlet chamber in which the dispersion pipe is not inserted. The flow rate of the refrigerant increases whenever the refrigerant passes through the opening. Therefore, the flow rate of the refrigerant in the refrigerant inlet chamber, in which the dispersion pipe is not inserted, is maintained enough.
In a third laminated type heat exchanger of the present invention, a plurality of said dispersion plates are provided in the refrigerant inlet tank, and the size of the openings formed at the dispersion plates decreases with an increase in the distance from the refrigerant gate portion. According to this laminated type heat exchanger, the flow rate of the refrigerant in the refrigerant inlet chamber, in which the dispersion pipe is not inserted, is maintained more enough.
A fourth laminated type heat exchanger of the present invention comprising:
a refrigerant inlet tank comprising a plurality of refrigerant inlet chambers, and in which a refrigerant passage passing through the refrigerant inlet chambers is formed;
a refrigerant outlet tank comprising a plurality of refrigerant outlet chambers, and in which a refrigerant passage passing through the refrigerant inlet chambers is formed;
a plurality of refrigerant pipes each having one end which is connected to the refrigerant inlet chamber and the other end which is connected to the refrigerant outlet chamber;
a refrigerant gate portion for flowing the refrigerant into the refrigerant inlet tank and from the refrigerant outlet tank;
a dispersion pipe which is inserted in the refrigerant passage formed in the refrigerant inlet tank;
wherein a restrictor for restricting the flow of the refrigerant is provided at the upstream side of the refrigerant passage in the refrigerant inlet tank.
According to this fourth laminated type heat exchanger of the present invention, the nozzle restricts the flow of the refrigerant from the refrigerant gate portion. When the refrigerant passes through the nozzle, a mist flow of the refrigerant is generated. Thereby, the flow rate of the refrigerant increases. The refrigerant reaches the inner refrigerant inlet chambers, and flows into the refrigerant pipes. Then, the refrigerant is dispersed uniformly in the laminated type heat exchanger.
In a fifth laminated type heat exchanger of the present invention, the restrictor is formed at an end plate of the refrigerant inlet tank.
In a sixth laminated type heat exchanger of the present invention, the refrigerant gate portion comprises a connection plate for flowing the refrigerant into the refrigerant inlet tank, which is connected to an end plate of the refrigerant inlet tank; and a restrictor for restricting the flow of the refrigerant is provided at the connection plate.
In a seventh laminated type heat exchanger of the present invention, at least one dispersion plate comprising an opening for restricting the flow of the refrigerant is provided in the refrigerant inlet tank and/or the refrigerant outlet tank. According to the seventh laminated type heat exchanger, the flow rate of the refrigerant in the refrigerant inlet tank is maintained enough.
In a eighth laminated type heat exchanger of the present invention, a plurality of said dispersion plates are provided in the refrigerant inlet tank and/or the refrigerant outlet tank, and the size of the openings formed at the dispersion plates decreases with an increase in the distance from the refrigerant gate portion. According to the eighth laminated type heat exchanger, the flow rate of the refrigerant in the refrigerant inlet tank is maintained more enough.